Power frequency variation
BSRIA Power quality guide (AG 2/2000) was written by C C Pearson and V Uthayanan and published by BSRIA in July 2000. It states:
Power frequency variations are defined as the deviation of the power system fundamental frequency from its specified nominal value of 50 Hz.
The power system frequency is directly related to the rotational speed of the generators supplying the system. There are slight variations in frequency as the dynamic balance between load and generation changes. The size of the frequency shift and its duration depends on the load characteristics and the response of the generation control system to load changes.
On modern interconnected power systems, significant frequency variations are rare. Frequency variations of consequence are much more likely to occur for loads that are supplied by a generator isolated from the utility system. In such cases, governor response to abrupt load changes may not be adequate to regulate within the narrow bandwidth required by frequency-sensitive equipment.
Voltage notching can sometimes be mistaken for frequency deviation. The notches may come sufficiently close to zero to cause errors in instruments and control systems that rely on zero crossings to derive frequency or time.
--BSRIA
[edit] Related articles on Designing Buildings
Featured articles and news
Plumbing and heating for sustainability in new properties
Technical Engineer runs through changes in regulations, innovations in materials, and product systems.
Awareness of the Carbon Border Adjustment Mechanism
What CBAM is and what to do about it.
The new towns and strategic environmental assessments
12 locations of the New Towns Taskforce reduced to 7 within the new towns draft programme and open consultation.
Buildings that changed the future of architecture. Book review.
The Sustainability Pathfinder© Handbook
Built environment agency launches free Pathfinder© tool to help businesses progress sustainability strategies.
Government outcome to the late payment consultation, ECA reacts.
IHBC 2025 Gus Astley Student Award winners
Work on the role of hewing in UK historic conservation a win for Jack Parker of Oxford Brookes University.
Future Homes Building Standards and plug-in solar
Parts F and L amendments, the availability of solar panels and industry responses.
How later living housing can help solve the housing crisis
Unlocking homes, unlocking lives.
Preparing safety case reports for HRBs under the BSA
A new practical guide to preparing structural inputs for safety cases and safety case reports published by IStructE.
Male construction workers and prostate cancer
CIOB and Prostate Cancer UK encourage awareness of prostate cancer risks, and what to do about it.
The changed R&D tax landscape for Architects
Specialist gives a recap on tax changes for Research and Development, via the ACA newsletter.
Structured product data as a competitive advantage
NBS explain why accessible product data that works across digital systems is key.
Welsh retrofit workforce assessment
Welsh Government report confirms Wales faces major electrical skills shortage, warns ECA.
A now architectural practice looks back at its concept project for a sustainable oceanic settlement 25 years on.
Copyright and Artificial Intelligence
Government report and back track on copyright opt out for AI training but no clear preferred alternative as yet.
Embedding AI tools into architectural education
Beyond the render: LMU share how student led research is shaping the future of visualisation workflows.
Why document control still fails UK construction projects
A Chartered Quantity Surveyor explains what needs to change and how.
Inspiration for a new 2026 wave of Irish construction professionals.
New planning reforms and Warm Homes Bill
Take centre stage at UK Construction Week London.

























